I always had that feeling when I saw mecha models that something was missing, and that was the fact that most hands weren't movable vertically(of course there are exeptions sometimes)...So I came up with this idea for my future models to have better poseability. I don't know if anyone else tought about this earlyer or not but I have never seen a hand built this way before.(Altough I have doubts if this would work with real life MOCs since I can't test it sadly ^^ oh well...)
I came up with this idea especialy for my Strike Noir Gundam, but I'll use the same method on other MOC's as well.

About this creation

Last pictures feature my "Kuro"(black) edition of the Zaku Warrior with the new arm design in use. Hope you guys like it and that I gave you something "new".

I can tell you for myself that, I've tried this very design in real lego, and even something like a beam sabre is far too heavy for it in most cases. If they have nothing to brace against, ball joints are extremely weak, unless you use the rubber coated ones.

Quoting Mithryl Dlarix
Its a great idea...on paper. If the hands don't have to hold well...anything, then these are a great idea. If any weight at all is put on them though, they will just sag down.

Yes I'm very aware of the big weekness of this design, however for smaller scale MOCs like my Zaku it would be good, since they don't have huge weapons to hold out. Of course, this is only theorytical, but for people who build LDD MOCs like myself, it's a very good thing.